SUMMARY The overall goals of this proposal are to elucidate novel male reproductive tract-specific proteins through high throughput transcriptomics and proteomics approaches, and to focus on the genetic analyses of five novel genes with expression limited to the male reproductive tract. With the world population continuing its steep rise, the need for effective and reversible non-hormonal methods of fertility control for men, such as those available to women, is widely recognized. To date, hormonal male contraceptives have not been effective. Therefore, identification of novel druggable targets in sperm and the male reproductive-tract are required to advance development of male contraceptives. Despite significant advances in proteomics, a comprehensive human sperm proteome has not been established. Likewise, despite extensive transcriptomic data published from mouse and rat epididymal segments, few published datasets exist for human epididymis. As sperm progress along the epididymal duct, they are bathed in a specialized luminal fluid microenvironment that is crucial for their maturation and survival. Considering its essential role, the epididymis is a prime target for the development of contraceptives for men. The proposed research is anticipated to lay the groundwork for future development of male contraceptives against novel targets. Motile, mature sperm are essential for successful fertilization and our overall hypothesis is that undiscovered druggable targets exist in the human male reproductive tract that are critical for sperm maturation and function. Our specific aims are as follows: 1) Perform transcriptomic analysis of human epididymal segments to identify novel epididymis-specific druggable targets to interfere with sperm maturation; 2) Perform proteomic analysis of human sperm to identify novel sperm-specific druggable targets for contraception; and 3) Apply CRISPR/Cas9 in mice to validate key sperm or reproductive tract-specific proteins required for sperm function and/or fertilization. The end goal of the proposed to work is to lead to the identification of additional novel targets for which an interdisciplinary team will work toward. Our mechanistic studies will allow us to place these proteins into reproductive pathways and simultaneously determine the utility of each of these proteins as a contraceptive target.